The next two Tests will reveal how strong South Africa’s depth is in the key positions of scrumhalf, blindside flank and outside centre, writes JON CARDINELLI.

How important are Fourie du Preez, Willem Alberts and Jaque Fourie, not only in terms of their individual play, but in the context of the Springbok game plan?

Du Preez is similar to an American football quarterback, in the way he reads the game and organises those around him. Willem ‘The Bone Collector’ Alberts smashes opponents back, and kills opposition momentum. Jaque Fourie's superior understanding of space in that No 13 channel ensures that the defence operates at optimum efficiency.

The Boks aren't as sharp when one of the three is missing. When all three are sidelined, which is presently the case, you can't expect the Boks to be at their brutal and clinical best.

Or can you? We live in an age when top-flight rugby is played almost every weekend, and injuries and absences are commonplace. The best teams cope with such losses, as they have quality in reserve.

This is why Heyneke Meyer has attempted to build a squad of 35 over the past three years. Meyer realises that it's a matter of when rather than if a star player breaks down with injury.

It's also a widely accepted fact that outstanding squads of 30-plus win big tournaments, not teams of 15. Remember the 2007 World Cup, where Frans Steyn stepped in for Jean de Villiers at No 12, and Danie Rossouw for Pierre Spies at No 8? And who could forget the All Blacks in 2011, who relied on their fourth-choice flyhalf, Stephen Donald, to kick the winning penalty in the World Cup final.

The Boks have suffered significant setbacks with the loss of Du Preez, Alberts and Fourie. That said, they now have an opportunity to test their depth in what is the toughest annual tournament in world rugby. If they can cope with such losses in the Rugby Championship, they can cope with similar setbacks in the buildup to a World Cup knockout match.

Since Du Preez went down with a season-ending ankle injury in late June, the pressure on South Africa's second-best scrumhalf has intensified. What Meyer will want to see over the next four games is whether Ruan Pienaar can maintain a high standard, especially on the tactical kicking and decision-making front.

Meyer has known since early June that Fourie would not be available. JP Pietersen started at outside centre in all three June Tests, but club commitments in Japan have ruled him out for the bulk of the Rugby Championship.

Rookie Damian de Allende has been entrusted with the responsibility since Pietersen's departure, but has looked uncomfortable in the position. The Bok defence has been inconsistent, especially in the wider channels. While it's unfair to place all the blame on De Allende, one has to remember that the No 13 plays a big role in organising the defence.

Jean de Villiers is a player better suited to the task. Moving De Villiers to No 13 will provide the Boks with the necessary experience in that position, and would allow De Allende to play a more familiar role at No 12. A switch in midfield will give the Boks the right balance, which will certainly be needed in the coming clashes against the Wallabies and All Blacks.

However, the Bok backs will struggle if their pack continues to lose the battles at the set pieces and collisions. Veteran lock Victor Matfield will make a timely return this week, but the Boks have been dealt a blow with news that Alberts will play no part on the Australasian tour.

The uncapped Warren Whiteley has travelled Down Under with the Boks, but will only come into consideration if there are further injuries. It seems likely that Marcell Coetzee will start at that important position of blindside flank against Australia this Saturday.

The feeling in the Bok camp is that Francois Louw and Duane Vermeulen are in terrific form, and need to be backed in their respective positions of openside flank and No 8. Louw was named Man of the Match for his efforts in Pretoria, while Vermeulen was the pick of the forwards in Salta.

Coetzee was one of the standouts for the Sharks during the Super Rugby competition, and that game-shaping form was again patent in the Tests against Scotland in Port Elizabeth and Argentina in Salta. He won't be playing in his preferred position of openside over the next couple of weeks, but he will have another game-shaping job to do.

Juan Smith was being too hard on himself when he denounced his own performance in Salta. He will be back in the mix before long, and he will provide Meyer with another world-class blindside flank option.

For now, it will be good to see what Coetzee can offer in a contest against the Wallabies and All Blacks. Breakdown battles don't come any tougher, and if Coetzee can pass that test, he will convince Meyer that he can cover 6 and 7 at the 2015 World Cup.

Meyer could be in for a few more selection headaches over the next fortnight, though, as several other players start to break down. Jannie du Plessis is visibly exhausted after a taxing Super Rugby season, and it was disappointing to see that his tighthead understudy, the multi-talented Frans Malherbe, has been ruled out for the rest of the season.

By the end of this year's Rugby Championship, we will know where the Boks stand in relation to the All Blacks. In the context of the 2015 World Cup, we will also have a good idea of the Boks' depth, and whether the second-stringers have what it takes to perform in the most testing of circumstances.

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